Underreamer.



mm) s'rnrns PATENT OFFICE.

JACOB C. SIEGRIS'I, 0F PITTSBURGH, PENNSYLVANIA.

UNDERREAMER.

Specification of Letters Patent. "Patented Nov. 12, 1912.

Application filed June 8, 1912. Serial No; 702,547.

To all whom it may concern citizen of the United States of America, re-

siding. at Pittsburgh, in the county of Alle gheny and State ofPennsylvania, have invented certain new and useful Improvements inUnderrean'iers, of which the following is a specification, referencebeing had therein to the accompanying drawing.

This invention relates to underreamers, and moreparticularly to thattype of tool employed for enlarging the bore of wells to permit of thelowering of easing.

he objects of my invention are to provide an underreamer having apositive expansion and contraction of the jaw, thereby eliminating allpossibility of the loss of a movable element to the parts of theunderreamer in a well hole, and to provide an underreamer withdetachable bits or jaws that are assembled in a manner to have a directbearing upon the reamer body when a blow is struck.

Other objectsof my invention are to provide an underreamer which, whenexpanded to working position, shall possess the maximum strength, and tofurnish the underreamer with pivoted levers by which the jaws or bits ofthe tool are retracted in order that the tool can be placed in thecasing of the well.

-Fu1'ther objects of my invention are-to provide an underreamer bodypossessing the requisite strength to withstand the stresses and strainsto which it is subjected when the undcrreamer is in use, and'to furnishthe underreamer with a bridge that braces the inner sides of the bits orjaws, preventing contraction when a blow is struck.

Still further objects of my invention are to provide an underreamer thatis inexpensive to manufacture, durable and highly efw ficient forthepurposes for which 1t is intended.

Vith the above and other objects in View, the invention resides in anovel construction, combination and arrangement of parts to behereinafter specifically described and then claimed.

Reference will now be had to the drawing,-. wherein like numerals denotecorresponding parts throughout the several views, in Which- Figure 1 isa side elevation of ,a port-ion of the underreamer, partly in section,showing the bits or jaws thereof in a retracted position. Fig. 2 is asimilar view showing the bits or jaws in an extended or expandedposition. Fig. 3 is a front elevation of the un derreamer partly brokenaway and partlyin section. Fig. 4 is a plan of a detached bit or jaw,and Fig. '5 is a horizontal sectional view of the underreamer.

An underreamer in accordance with this invention comprises a cylindricalbody'l having the upper end thereof provided with the usual screwthreaded stem 2 to screw into the socket of the sub. The reamer body 1has a longitudinal:central bore 3 and said bore is in communication witha conically shaped chamber t that s formed in the lower end of thereamer body. The lower end of the reamer body l'is beveled, as at 5 andprovided with sets of oppositely disposed longitudinal slots 6 that arein communication with the chamber 4.

Arranged in the bore 3 and extending into the chamber lis a rod '7 thatis encircled by a coiled spring 8-within the bore 3, said spring holdingthe rod 7. The rod 7 within the chamber at is reduced and pivotallyconnected to the reduced end of said rod by a bolt 9 or other fasteningmeans is a link 10. Connected to the link 10 isa coiled retractilespring 11 and the lower end of said spring is connected to. the eye endof a stem 12, said stem supporting abridge 18 atthe lower end thereof.The stem 12 is provided with a transverse pin 1.4:, and loosely mountedupon the end of said pin are the inner slotted ends of L shaped levers15 that are fulcrumcd upon transverse pins 16 carried by the walls ofthe slots 6. The L shaped endsof the levers 15 protrude from the slots 5and when said levers are moved the bridge- 13 is adjusted.

Arranged -within the chamber 4 are oppositely disposed jaws 17 of agreater length than the chamber 4. The outer sides of the jaws 17 taperand the confronting sides thereof are provided with V shaped grooves 18,said grooves confronting: each other, as

BEST AVAILABLE COPY best 'shown'i-n Figa2 arid clearance for the spring11. The sides of the jaws" 17 are cut away, as at 19 to provideclearance for the levers 5-15, and saidilevers are slotted,

as at 20 to receive pins 21 carried by'the sides of the-jaws 17, withinthe cut away por-.

tion 19. I a v The upper ends of the jaws 17 are provided with beveledextensions 22 adapted to engage in beveled sockets 23 provided thereforin the top of the chamber 4. The lower ends of the jaws 17 terminate inbits 24 and the confronting faces of said bits are provided with pockets25 to receive the end extensions of the bridge 13 The outer faces of thebits 24 are rounded, as at 26 and the upper ends of said bits arebeveled, as at 27 the bits24by screw bolts 31 or similar fasteningmeans. The cutters 30 have cutting edges rotruding outwardly from thebits 26 and tese cutters are made of a material whereby they can be usedwhen shale or rocks are encounteredfj; 'The cutters 30 can i beeasily'removed and sharpened and these detachable cutters form animportant adjunct-of my invention as they permit of the underreamerbeing used in the California oil fields, wherea hard and indurate shaleor strataof rock is encountered when drillglo brace the bits 24, thelower end of the reamer body 1 is provided with sets of depending sides0 the hits 24, as best shownin F ig. 3 and prevent said hits fromshifting relative to the reamer body 1.

In practice, the clamp or suitable device is placed-around theunderreamer body 1 to engage the outer ends of the levers 15 and forcethe ends of said levers within the slots 6. With the lovers 15 heldwithin the slots 6, the bridge 13 is retained in a lowered posi tionwith the spring ll under tension. With the bridge 13 engaging in thepockets 25 of the bits 24, the bits are in a retracted position beneaththe underreamer body, as best shown in Fig. 1. The jaws 17 are thereforelowered ahd as the link 10 is carried by the upper ends of the jaws 17,the coiled spring 8 surrounding the rod 7 is under tension. j

With the bits 24 in a retracted position, the unde'rreamer can be placedin a casing or tubing and after the bits have-been placed in the casingof a well hole, the clamp or die vice employed for holding the outerends of Y230 are furthermore connected tov pins 32 and. these pinsengage the.

walls of the well casing. The bits 24 are still retained ina retractedposition out of engagement with the walls of the well casthelower end ofthe casing. As the underreamer, particularly the lower end thereof,passes out of the lower end of the casing into the well hole, the spring11 immediately the bits 24 apart, as bestshown in Fig. 2. The spring 8also cooperates with the spring 11 and the jaws 17 are elevated. 'As thethe extensions 22' of said jaws engage in the top of the chamber and theup er bbveled ends of the bits 24 engage the eveled end of theunderreamer'body. The jaws 17 are and as the up e'r ends of the jaws andthe upper ends 0 the bits engage the unde reamer body, the entirestructure is capabgg of receiving a heavy blow. j

When the underreamer body is to be ends of the bits 24 are forcedinwardly d of the well casing, said cutters are f d inwardly, but suchmovement ofthe'bi d cutters does not occur except whe th bridge isreleased by the levers 15, m the outer ends of the levers 15 encounterthe lower end of the well casing and alz hift d casing engagin the bits24. Whe th 1 vers 15 are shi ted, thebridge 13 i l d and the bits 24 canassume a retf t d sition.

tion of the underreamer will r nt without further description. a d hilein the drawing there is illustrated a f rred embodiment of the.inyention, i, i t b ceptible to such variations an difi ti as fallwithin the scope of I th d d claims.

What I claim is:

jaws movable in said bod d xt nding from the lower end' thereo leversivotally mounted in said bodyjand, h i g t e inner ends thereof looselycon p to shift liid jaws and sai when said levers a l d In a i-eamer, achambered-body,

levers braced against the walls of the chamber 4,

the levers 15' is removed, thereby allowing 68 the ends of theleverstoengage the inner.

ing, and the underreamer can be lowered to 70 elevates the bridge 13,thereby removing the bridge from the pockets 25, thereby forcing jaws 17move upwardly into the chamber 4, 86

90 moved from a well hole, the upper bev d when thecutters 30 encounterthe lower d inwardly, prior to the lower end of h ll It is thoughtflthatthe utility d e derstood that the structural clej t are $113.

'1. An underreamer com i i a body,

ted to said jaws and the outer ends ther f d t d t and means c nn ted-tosaid brid e and 12b jaws extending into said chambered body, Intestimony whereof I affix my signzi inre bits earned by said jaws,levers pivotally in the presence of two witnesses.

mounted in said body and loosely connected to said jaws, a bridgearranged between said JACOB SIEQRIST' 5 jaws and means connected to saidbridge and Vfitnesses:

to said levers for expanding said jaws when Mex SROLOVITZ said leversare released. ELH. BUTLER.

